在iOS中tabView的使用频率相当之高,在android中对应的控件ListView应该也不例外,下面看下ListView的使用:(-)
Adapter
首先我们来看看他的继承结构图:
上面就是Adapter以及继承结构图了,接着我们介绍一下实际开发中还用到的几个Adapter吧!
BaseAdapter:抽象类,实际开发中我们会继承这个类并且重写相关方法,用得最多-的一个Adapter!
ArrayAdapter:支持泛型操作,最简单的一个Adapter,只能展现一行文字~
SimpleAdapter:同样具有良好扩展性的一个Adapter,可以自定义多种效果!
SimpleCursorAdapter:用于显示简单文本类型的listView,一般在数据库那里会用到,不过有点过时, 不推荐使用!
e.g. 要达到如下效果
第一步,自定义Adapter
AnimalAdapter.java:自定义的BaseAdapter:
package com.example.bf.listview_f;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.LinkedList;
/**
* Created by bf on 2017/2/15.
*/
public class AnimalAdapter extends BaseAdapter {
private LinkedList<Animal> mData;
private Context mContext;
public AnimalAdapter(LinkedList<Animal> mData, Context mContext) {
this.mData = mData;
this.mContext = mContext;
}
@Override
public int getCount() {
return mData.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.item_list_animal,parent,false);
ImageView img_icon = (ImageView) convertView.findViewById(R.id.img_icon);
TextView txt_aName = (TextView) convertView.findViewById(R.id.txt_aName);
TextView txt_aSpeak = (TextView) convertView.findViewById(R.id.txt_aSpeak);
img_icon.setBackgroundResource(mData.get(position).getaIcon());
txt_aName.setText(mData.get(position).getaName());
txt_aSpeak.setText(mData.get(position).getaSpeak());
return convertView;
}
}
第二步,定义Animal类,包涵Name,Speak,Icon( M ) Animal.java
package com.example.bf.listview_f;
/**
* Created by bf on 2017/2/15.
*/
public class Animal {
private String aName;
private String aSpeak;
private int aIcon;
public Animal() {
}
public Animal(String aName, String aSpeak, int aIcon) {
this.aName = aName;
this.aSpeak = aSpeak;
this.aIcon = aIcon;
}
public String getaName() {
return aName;
}
public String getaSpeak() {
return aSpeak;
}
public int getaIcon() {
return aIcon;
}
public void setaName(String aName) {
this.aName = aName;
}
public void setaSpeak(String aSpeak) {
this.aSpeak = aSpeak;
}
public void setaIcon(int aIcon) {
this.aIcon = aIcon;
}
}
第三步 MainActivity.java
package com.example.bf.listview_f;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.app.Activity;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Toast;
import java.util.LinkedList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener{
private List<Animal> mData = null;
private Context mContext;
private AnimalAdapter mAdapter = null;
private ListView list_animal;
private LinearLayout ly_content;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
list_animal = (ListView) findViewById(R.id.list_animal);
//动态加载顶部View和底部View
final LayoutInflater inflater = LayoutInflater.from(this);
View headView = inflater.inflate(R.layout.view_header, null, false);
View footView = inflater.inflate(R.layout.view_footer, null, false);
mData = new LinkedList<>();
mData.add(new Animal("狗说", "你是狗么?", R.mipmap.ic_icon_dog));
mData.add(new Animal("牛说", "你是牛么?", R.mipmap.ic_icon_cow));
mData.add(new Animal("鸭说", "你是鸭么?", R.mipmap.ic_icon_duck));
mData.add(new Animal("鱼说", "你是鱼么?", R.mipmap.ic_icon_fish));
mData.add(new Animal("马说", "你是马么?", R.mipmap.ic_icon_horse));
mAdapter = new AnimalAdapter((LinkedList<Animal>) mData, mContext);
//添加表头和表尾需要写在setAdapter方法调用之前!!!
list_animal.addHeaderView(headView);
list_animal.addFooterView(footView);
list_animal.setAdapter(mAdapter);
list_animal.setOnItemClickListener(this);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(mContext,"你点击了第" + position + "项",Toast.LENGTH_SHORT).show();
}
}
第四步 表头 view_header.xml(表头),表尾一样,就不贴了:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:gravity="center">
<TextView
android:layout_width="match_parent"
android:layout_height="48dp"
android:textSize="18sp"
android:text="表头"
android:gravity="center"
android:background="#43BBEB"
android:textColor="#FFFFFF"/>
</LinearLayout>
图片放在了如下的文件目录下,这样图片的大小是icon的大小
当然还有至关重要的一个 item_list_animal.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="44dp"
android:layout_height="44dp"
android:id="@+id/img_icon" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="fill_parent"
android:layout_height="22dp"
android:id="@+id/txt_aName" />
<TextView
android:layout_width="fill_parent"
android:layout_height="22dp"
android:id="@+id/txt_aSpeak" />
</LinearLayout>
</LinearLayout>